Forced-feed internal-combustion engine



Apr'xl 19, 1927.` G. FORNACA Foncsn man INTERNALv coususTIou ENGINE Filed D66. 18. 1924 type, that is,

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Patented Apr. l19, 1927.

UNITED STATES GUIDO FORNACA, 0F TURIN, ITALY.

FORCED-FEED INTERNAL-COMBUSTION ENGINE.

App'lication filed December 18, 19.24, Serial No. 756,762, and in Itaiy December 22, 1923.

This invention relates to forced feed internal combustion engines of theyso called V- the ltype in which there are two sets of cylinders arranged in V-form.

It has been proposed to construct an engine of this type in which the .cylinders are cast integral with the crank case.

. The object of the present invention is to simplify the construction of such engines still further, and to the attaiun'ient of this object the invention consists in arranging the forced feed compressor between the sets Vof cylinders and in casting the casing of said compressor in one with the cylinders .and lwith the crank case or the upper part thereof.

The cylinders may have liners separate from the casting which liners may aluminium so as to obtain an engine of light weight as required for aircraft.

Three examples of engine construction in accordance with the invention are shown on the appended drawing.

Fig. 1 shows (in section) a form in which all the principal parts of the engine are cast in a single piece.

Fig. 2 shows (in section) another form 'in which liners and cylinder heads ,are fittedseparately. l

Fig. 3 shows (in section) a third form in which the, lower part of the engine casing is fitted separately.

Referring first more particularly to Fig. 1, the crank casing 1 is cast in one with the cylinders 2, the cylinder jackets 3, the cylinder heads/1, and the body 5 of the forced feed compressor. Access to the interior of the purpose of machining same 4is obtained through openings 6 provided in the lower part of the engine casing. The fitting up of the engine is no more A complicated than that of an ordinary engine.

The pistons 9 l(after. the connecting rods 10, 11 have been fitted thereto) are inserted in the cylinders through the openings 6; the' crank shaft is inserted through one end of' the engine casing provided for that purpose with a suitable cover; the bearing caps'of (the connecting rods and the main bearing 50 caps are fixed. 'n position through said openings and finally said openings are closed by 'means of suitable covers.

In-the construction illustratedby Fig. 2, the crank casing 2, the cylinder jackets 3,

and the'compressor body 5 are cast in one then be. madeof steel while the casting may be'ofsupplied j sible to make piece as before but the cylinders 8, preferably of special high strength steel, are mounted separately as are the cylinder heads.

- This construction is without the openings 6 for the main casting such as could not be y used for the cylinders proper owing to the very high temperatures to which the latter are subjected.-

lAs shown in Figs. 1 and 2 the body or casing 5 of the forced feed compressor is mounted between, and is connected to the two sets otl cylinder jackets 3, 3 by webs 12 cast integral with said casing and jackets. The form and arrangement of the webs (only one of which is shown on each side of the'casing) are such that they form the sides of conduits for the admission of air to the compressor, the tops and bottoms of said conduits beinfr constituted by the walls of the casing an cylinders respectively. Said conduits are open at their upper ends 13 and converging downwardly communicate at their lower ends with the casing 5, through an opening 14 in the bottom `of the latter. l

Air is drawn through the conduits and through the opening 14 into ythe bottom of the compressor by the rotation of the couipressor blades 15 andA operates, during its passage through said conduits as a cooling medium for the cylinders andis therefore to the compressor in a heated condition. The heated compressed air is discharged from Vthe compressor through an opening 16 in the top of the latter and into a conduit 17 inthe lower end of which a carburetter 18 discharges. Each conduit 17 has two branch conduits 19 which communicate with the cylinders through the heads 4 as shown in Fig. 1.

In the construction illustrated by Fig. 3, the lower part of the crank casing 2 is made and fitted separately with the object of rendering the engine still lighter, as it is posthis part, which is not subject to any considerable mechanical strain, of stamped or sheet aluminium.

In all cases the carburetter is preferably fitted immediately at the point. of delivery of the compressor, so that the compressed air passes directly through long pipes.

That I claim is:

thereto Without passing A forced feed internal combustion engine 5 of the V-type consisting of a single casting comprising' the upper part of the crank case,

two cylinders, and t he' casing for the forced GUIDO FORNACA. 

